n : an apparatus for the production of electrical discharges at high voltage commonly consisting of an insulated hollow conducting sphere that accumulates in its interior the charge continuously conveyed from a source of direct current by an endless belt of flexible nonconducting material - called also electrostatic generator

Van de Graaff, Robert Jenison (1901-1967), American physicist. Van de Graaff developed his generator as a device for producing the very high voltages necessary to accelerate particles to energies high enough to create new elements heavier than uranium. He built his first machine in the early 1930s, and in 1946 he cofounded a company to manufacture particle accelerators incorporating the Van de Graaff generator. These particle accelerators have found widespread use in medicine and industry as well as in high-energy physics research.